desktop: opening a subfolder roots new sessions at the git repo root, so its .opencode agents are not found #57583

Summary

In OpenCode Desktop v2.1.x, opening a subfolder of a git repository that has its own .opencode/opencode.json (defining custom agents) still roots newly created sessions at the git repo root instead of the opened subfolder. Agents defined in the subfolder's config are therefore not registered for those sessions, and using them fails with Session.AgentNotFoundError: Agent not found. The same setup worked in 2.0.x, where sessions were rooted at the opened folder.

Environment

• opencode version: 2.1.1 (also reproduced on 2.1.0)
• OS: Microsoft Windows [Version 10.0.17763.737] (win32 x64)
• Terminal: N/A (desktop app, @opencode-aidesktop)
• Shell: C:\Windows\system32\cmd.exe
• Install/channel: latest (desktop app auto-update; service versions observed: 2.0.32 → 2.1.0 → 2.1.1)
• Active plugins: superpowers@git+https://github.com/obra/superpowers.git (project config). Note: 4 legacy V1 plugin files under ~/.config/opencode/plugins/ fail to load with Cannot find package '@opencode-ai/plugin' — unrelated to this issue.

Reproduction

1. Have a git repo <repo> containing a subfolder <repo>/docs/ with its own .opencode/opencode.json that defines an agent (e.g. wiki-agent, mode: primary) and sets "default_agent": "wiki-agent".
2. In OpenCode Desktop, open the docs/ folder directly as a window/project.
3. Create a new session in that window and use wiki-agent (either explicitly selected or via default_agent).
4. Send any message.

Expected Behavior

The new session's location is <repo>/docs, the subfolder config is discovered, and wiki-agent is available. This was the behavior in 2.0.x — sessions created this way had directory = <repo>/docs.

Actual Behavior

• The server does boot the subfolder location and registers its agents there (log: location services booted directory="<repo>\docs", followed by agent.updated events with event.location.directory="<repo>\docs").
• However, the newly created session is persisted with directory = <repo> (git repo root), not the opened subfolder.
• Sending a message fails:

level=ERROR message="Failed to drain Session" cause="Session.AgentNotFoundError: Agent not found: \"wiki-agent\""

Control experiments showing the server side works correctly when the session location is actually the subfolder:

1. GET /api/agent?location[directory]=<repo>/docs → wiki-agent is present (mode primary, permissions parsed).
2. POST /api/session with {"agent":"wiki-agent","location":{"directory":"<repo>/docs"}} + a prompt → session completes with outcome: "succeeded".
3. Running the CLI from <repo>/docs (opencode run "ping") → session runs as wiki-agent and succeeds.

Additional Context

• Reproduced consistently over two consecutive days across two service instances (v2.1.0 and v2.1.1), multiple attempts, including after explicitly re-opening the subfolder.
• The desktop app does request the subfolder location: location services booted directory="<repo>\docs" is logged immediately before session creation, yet the created session row has directory = <repo> and empty path.
• Historical 2.0.x sessions created in the same subfolder have directory = <repo>/docs, so this appears to be a behavior change introduced in 2.1.x (session location now resolves to the git project root).
• Workaround: run the CLI/TUI with cwd set to the subfolder — sessions are then rooted correctly and the subfolder agent works as expected.